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Milwaukee River Basin's Water Quality Decline: 'It's Hard To Sugarcoat'

Katie Rademacher
Cheryl Nenn check temperature of Pigeon Creek where it meets Mee-Kown Creek in Ozaukee County. Pigeon is one of the higher scoring creeks in the Milwaukee River Basin.

The Milwaukee River Basin scored a C- for water quality in 2017. The grade has dropped to a D, according to a report recently released by Milwaukee Riverkeeper.

But that doesn't mean the entire 882-plus square mile basin that begins in Sheboygan and Fond du Lac counties is one big mess. For example, Pigeon Creek in Ozaukee County earned a B-. The creek is a tributary of the Milwaukee River, one of three rivers that fall within the basin.

"From where we’re standing on Pigeon Creek, there’s probably 300 acres upstream of protected habitat and a lot of spawning wetlands that are available for fish like northern pike and other natives. We’ve also started seeing a lot of migrating salmon coming up here in the fall,” says Cheryl Nenn, who's with Milwaukee Riverkeeper.

In spring, summer and fall, more than 80 of its volunteers monitor dozens of spots throughout the Basin.  The annual water quality ranking is a distillation of that information, along with data collected by Milwaukee Metropolitan Sewerage District, the Wisconsin Department of Natural Resources, and the Ozaukee County Parks and Planning Department. Together, Nenn says they measure key factors — or parameters — that influence water quality, including temperature.

Credit Milwaukee Riverkeeper
The Milwaukee Riverkeeper recently released a report grading the water quality of the Milwaukee River Basin. Shown here is a map of the Milwaukee River Basin with the grades, which range from green A to a red F. (Click to enlarge)

"If the temperature is too high, then a lot of fish can’t survive, basically, and it can also impact other aquatic life in the stream because temperatures are very much correlated with oxygen level," Nenn says.

Why is the amount of oxygen dissolved in a stream important? Nenn says imagine you’ve opened a can of Coke in your car on a warm summer’s day.

"The hot Coca-Cola goes flat because all of the oxygen is released. It’s kind of similar with the river. As the river warms it can hold less oxygen. There’s less oxygen in the river then for fish, and aquatic life and invertebrates that are really the base of the food chain in the river," Nenn explains.

The Milwaukee River Basin is made up of three rivers: Milwaukee, Menomonee, and Kinnickinnic rivers. Each one forms unique watersheds. She says the Milwaukee is still pretty natural, about 80% rural. But the Kinnickinnic is about 95% urban. The Menomonee is about 80% urban — and developing. 

Despite their differences, all three watersheds are burdened with high levels of phosphorus. High levels in waterways can throw the ecosystem off balance through toxic algal blooms, oxygen depletion and fish kills.

"In a nutshell, a lot of those baseline parameters are doing pretty well – temperature, oxygen, that’s great. But we’re still really challenged by phosphorus, which is coming from fertilizers, manure," Nenn says.

Credit Milwaukee Riverkeeper
Samples being taken along the Kinnickinnic River at stormwater outfall.

High concentrations of bacteria also compromise the basin’s health. Think E.coli and fecal coliform – just two forms of bacteria that are bad for both aquatic and human life. Nenn says nuisance bacteria finds its way into the system through multiple pathways.

This time of year, Riverkeeper volunteers transition to winter road salt monitoring. Road salt is essentially chloride. Although it’s good at handling icy pavement, the chemical compound is deadly to rivers and streams.

"We're still not where we want to be. D is not a grade you want to take home to mom."

"Too much salt can be really toxic for fish and aquatic life. We have quite a few creeks that are at levels where they’re almost instantly toxic to fish in the stream," Nenn says.

Keeping up with threats to the Milwaukee River Basin is daunting.

"We're still not where we want to be. D is not a grade you want to take home to mom. It’s not good and it’s hard to sugarcoat that," Nenn says.

Credit Milwaukee Riverkeeper
Early 2019 road salt monitoring along Trinity Creek, a tributary of the Milwaukee River.

Yet, Nenn insists there are signs of improvement. Milwaukee Riverkeeper’s efforts include driving down the amount of chloride entering the basin.

"We’re doing a lot of education of private homeowners [and] training events with municipalities ... They’re incentivized to do that because it can save them a lot of money. Some cities pay hundreds of thousands of dollars each year on salt bills," Nenn says.

Phosphorus presents an even thornier challenge. A lot of the phosphorus-laden runoff that enters the basin comes from farms, but Nenn says farming practices are evolving.

"There's a Cedar Creek farmers group and there's another farmer collaborative in Ozaukee County that’s really working on promoting best management practices and more no-till and more agricultural practices that really focus on improving soil health and keeping soil in place,” Nenn says. “It's important to keep our highly productive soil on the land where the farmers can use it, and not getting into the river where it's gonna cause problems.”

"It's important to keep our highly productive soil on the land where the farmers can use it, and not getting into the river where it's gonna cause problems."

In 2018, the EPA approved pollution reduction plans for all three of the basin's rivers for several sources of contamination. The plans are called Total Maximum Daily Loads. Nenn says the plan amounts to a pollution diet.

"It’s essentially a plan to ratchet down sources of phosphorus, and also sources of sediment and sources of bacteria," she explains.

Now what’s needed, Nenn says, is a strong and effective implementation to make the diet stick.

As if the basin didn't have enough threats, stormwater is another. Nenn says record-breaking precipitation in 2018 contributed to the Milwaukee River Basin’s overall water quality decline.

"We’ve been getting these extreme wet weather events more and more frequently, which is pretty in line with the climate change models. We’re seeing 100-year storms it seems like every couple of years. The rivers are incredibly high going [into] fall here and we’re starting to see ice already," Nenn says.

Credit Cheryl Nenn
Naturalization in progress along the Kinnicknnic River in Pulaski Park.

Milwaukee Metropolitan Sewerage District — commonly called MMSD — is attempting to reduce flooding along the most developed of the basin’s three watersheds: the Kinnickinnic. Crews straightened and lined it the Kinnickinnic with concrete in the 1960s. At the time, channelizing rivers was considered state-of-the-art flood control. Instead, flooding intensified.

MMSD is now naturalizing the Kinnickinnic — and riverkeeper Cheryl Nenn is thrilled.

"When I moved here 17 years ago, I never thought I’d see that. And we have big plans to remove concrete, basically, from Miller Parkway down on the Kinnickinnic River, providing a reconnection to floodplains, trying to naturalize it as much as we can," she explains.

READ: When It Comes To Flooding, Can Milwaukee Cope?

Nenn says smaller green infrastructure projects are also making a difference.

"People are really pushing more and more of that because I think it, basically, helps minimize flooding. Those plants often are very beautiful and they have a really important water quality function that they can play," Nenn says.

Credit Susan Bence
Every spring more than 4,000 volunteers help clean up nearly 60 sites throughout the Milwaukee River Basin. Cheryl Nenn says that's proof public awareness is growing.

Milwaukee Riverkeeper remains focused on its mission to achieve swimmable, fishable AND drinkable rivers and waterways in the Basin.

"There’s a lot of planning going on in the watershed that kind of identify what’s impairing these creeks. Where is the sediment coming from, where is the phosphorus coming from, where is the bacteria coming from? Are there bad pipes, bad septic," Nenn adds "We have the data now to show us where those hotspots are and to really guide us toward solutions that result in these grades getting better over time."

In Nenn’s opinion, public awareness is getting better and better. That’s her greatest source of optimism for a healthy future of the Milwaukee River Basin.

Have an environmental question you'd like WUWM's Susan Bence to investigate? Submit below.


Susan Bence entered broadcasting in an untraditional way. After years of avid public radio listening, Susan returned to school and earned a bachelor's degree in Journalism from the University of Wisconsin-Milwaukee. She interned for WUWM News and worked with the Lake Effect team, before being hired full-time as a WUWM News reporter / producer.